getBody on attachments sends and empty attachment

[rabas]

The issue seems to be that calling getBody on Swift_Mime_SimpleMimeEntity before actually sending the email makes the given attachment empty.

Body of the attachment is read from the file, and it is instance Swift_ByteStream_FileByteStream. So when I call getBody it does return a string containing the body of an attachment. But the attachment is empty.

I can reproduce this by calling getBody twice:

var_dump($attachment->getBody());
// Dumps a string that contains attachment body

var_dump($attachment->getBody());
// Dumps an empty string 

As far as I can tell, read method of Swift_ByteStream_FileByteStream does not reset read handle correctly, because when I call $os->setReadPointer(0) before return of the _readStream method of the Swift_Mime_SimpleMimeEntity body is correctly returned each time.

Edit: Swiftmailer version is Swift-5.2.2-DEV and PHP version is PHP 5.6.0